1. Field of the Invention
The present invention relates to pump operated, water saving plumbing fixtures, such as toilets and urinals, and more particularly to controlling operation of the pump in such plumbing fixtures.
2. Description of the Related Art
Historically, toilets have a reservoir above the level of a toilet bowl so that, upon activation of the flush valve, water is fed by gravity from the reservoir into the toilet bowl. In the past typically three or more gallons of water was required for flushing the toilet. In recent years, the efficiency of such gravity fed toilets has been improved to the extent that in many cases 1.6 gallons of water is sufficient to remove waste from the bowl. However, where especially large amounts of feces are present, double flushing often was needed to remove the waste completely.
A solution to the necessity to double flush a toilet while still using a reduced quantity of water is to pressurize the flush water entering the toilet bowl. U.S. Pat. No. 5,542,132 describes a toilet in which a pump draws water from a reservoir and feeds the water under pressure to the bowl. To achieve optimal water conservation the pump should supply just enough water to completely cleanse the bowl. However, manufacturing tolerances and altered alignment of parts can affect the water flow and thus adversely affect the flushing ability. Therefore a need exists to adjust operation of the pump for maximum efficiency with a given toilet.
In addition, many pump style toilet have the reservoir located beneath the bowl for compactness as gravity flow no longer dictates the reservoir location. However, if this type of toilet becomes plugged, there is a possibility that an excessively high level of soiled water in the bowl may enter the rim outlets thereby contaminating the reservoir. At the completion of a flush, water in the conduit leading to the bowl rim flows back downward into the reservoir drawing air into the conduit. Upon the next flush that air is forced through the rim outlets, which produces an objectionable hissing sound, as well as delaying delivery of water into the bowl.
Thus a need exists for an improved pump operated plumbing fixture.